1. Field of the Invention
The present invention relates to a voice activate transmitting device for a two way radio (or walkie-talkie) without incurring a losing words effect.
2. Description of the Invention
A conventional two way radio (or walkie-talkie) according to the prior art is shown in FIG. 1, and comprises a transmitting/receiving circuit, and a microphone amplifying circuit. The transmitting/receiving circuit comprises a demodulation circuit 11, mixers 12 and 14, a bandpass filter circuit 13, a down converter circuit 15, a transmitting/receiving signal interchange circuit 16, a filter circuit 17, a common antenna 18, a quartz oscillation circuit 19, a modulation circuit 20, an up converter circuit 21, a noise filter circuit 22, a lowpass filter circuit 23, an audio filter circuit 27, a microprocessor 28, a receiving circuit power supply control unit 29, a transmitting circuit power supply control unit 30, an identification code generating circuit 31, a loudspeaker control circuit 32, an amplifier 34, and a loudspeaker 33, etc. The microphone amplifying circuit comprises a microphone control circuit 24, an amplifier 25, and a microphone 26.
By such an arrangement, when the user is intended to use the two way radio, he/she has to press a push button such that the transmitting circuit of the two way radio can transmit a voice signal. However, the related circuits will reach a steady working state during a period of time due to the capacity effect or others thereof, hereby causing a "transmitting delay" such that when the user talks to the two way radio before the related circuits reach the steady working state, part of the voice message cannot be received or will be lost by the receiving circuit of another two way radio of the other party, thereby making the voice message not perfect such that the other party easily misunderstands what the user means. In addition, the transmitting circuit and the receiving circuit of the two way radio both communicate with the outside through the same channel such that the transmitting circuit and the receiving circuit cannot be operated simultaneously. Therefore, when two opposite parties transmit voices simultaneously, the two opposite parties cannot actually receive the voice signals. Moreover, the user has to press the push button when he/she is intended to use the two way radio, thereby causing inconvenience to the user. The present invention has arisen to overcome the disadvantages of the conventional two way radio.